The present invention generally relates to the migration of data from one storage location to another. More specifically, the present invention relates to the hierarchical state based migration of structured data.
Picture archiving and communication systems (“PACS”) connect to medical diagnostic imaging devices and employ an acquisition gateway (between the acquisition device and the PACS), storage and archiving units, display workstations, databases, and sophisticated data processors. These components are integrated together by a communication network and data management system. A PACS has, in general, the overall goals of streamlining health-care operations, facilitating distributed remote examination and diagnosis, and improving patient care.
A typical application of a PACS system is to provide one or more medical images for examination by a medical professional. For example, a PACS system can provide a series of x-ray images to a display workstation where the images are displayed for a radiologist to perform a diagnostic examination. Based on the presentation of these images, the radiologist can provide a diagnosis. For example, the radiologist can diagnose a tumor or lesion in x-ray images of a patient's lungs.
A series or sequence of a plurality of medical images is an imaging study. In order to properly diagnose a current imaging study, a radiologist must examine one or more previously acquired images of the same patient and compare these images to images of a current study.
For a particular hospital or clinic, the amount of computer readable storage used to store the imaging studies for patients of the hospital or clinic can be substantial. In addition, from time to time, a hospital or clinic may desire to update or alter its storage medium used to store one or more of the imaging studies of its patients. For example, medical imaging applications are currently heavily dependent upon the underlying storage technology used to store the medical imaging studies. The average life cycle of a particular storage technology is approximately five years. Therefore, a hospital or clinic may have to update its storage solution frequently, thus requiring the migration of a considerable amount of data (i.e., terabytes of data) to avoid storage obsolescence. For example, in the past a hospital may have used a tape storage solution for storing the imaging studies of its patients. However, the hospital may desire to switch to a computer disk storage solution, for example.
Moving, or migrating, the imaging studies from the old storage solution to the new storage solution can involve a considerable amount of time. When such a migration of imaging study data occurs, traditional systems and methods for migrating data prevent access to the imaging studies being migrated until the migration is complete. For example, a physician or radiologist cannot access imaging studies being migrated by traditional systems and methods during the data migration. Specifically, imaging studies may be accessed by a physician or radiologist using a workstation in a PACS system. The physician or radiologist may access a database of meta data links (or hyperlinks) that associate one or more imaging studies with a patient. By clicking on the link, the imaging study(ies) for a particular patient may be accessed and presented on the workstation. However, during data migration using traditional systems and methods, the link to the imaging study(ies) is not accurate during the migration. That is, a physician or radiologist may not access one or more imaging studies using the link in the database if the link does not direct the workstation to the current location of the data during the migration.
In addition, during the migration of data using traditional systems and methods, the migration occurs in a bulk manner. In other words, the migration traditionally occurs by moving entire imaging studies and/or multiple imaging studies at once. The process of copying the data to the new storage location cannot be stopped and started during the data migration. In this way, imaging study data has only two states in the traditional data migration—pre- and post-migration. Traditional systems and methods do not provide for additional states of data migration (so that the data migration can be stopped and re-started at various states).
Moreover, traditional systems and methods are static in their allocation of migration resources. That is, traditional systems and methods allocate resources (such as computer copying scripts) to migrate data from a legacy storage medium to a new storage solution before the migration occurs. However, these systems and methods do not allow for any updating of this allocation of resources during the data migration. For example, current migration systems and methods do not allow for the re-allocation of migration resources during the migration in order to provide for a more efficient data migration.
Therefore, a need exists for an improved method of migrating data from a legacy storage solution to a new storage solution. Such an improved data migration offers the ability to interrupt the migration at any point, to restart the migration at a point of interruption, to access the data at any time during the data migration, and/or to reallocate migration resources during the data migration.